Birds evolved through many smaller steps of earlier life-forms based on inherited traits that allowed for advantages in an environment over other similar animals. These traits were passed on to future generations. Over many generations, these small changes over time can add up making later generations look and act very different from earlier generations.
Birds evolved through many smaller steps of earlier life-forms based on inherited traits that allowed for advantages in an environment over other similar animals. These traits were passed on to future generations. Over many generations, these small changes over time can add up making later generations look and act very different from earlier generations.
Evolution of the Feather
Instinctive Behaviors Birds today inherited from ancestors
http://evolution.berkeley.edu/evolibrary/article/evograms_06